Beyond the answers - interesting background to this quiz

Two capitals that were built rather than inherited

Banjul and Brasília share an unusual trait: both are purpose-built capitals rather than the largest city of their country. Banjul sits on St Mary's Island at the mouth of the Gambia River, a small city that has served as the country's administrative centre since the colonial period. Brasília is far younger, planned from scratch in the 1950s and inaugurated in 1960 as a way of pulling Brazil's centre of gravity inland, away from the crowded coast. Its bold modernist layout later earned it UNESCO World Heritage status.

The Andean grain that is not really a grain

Quinoa is often called a pseudocereal because it is not a grass like wheat or rice, but a seed from a flowering plant related to spinach and beetroot. It was domesticated thousands of years ago in the Andes, where it became a staple for civilisations including the Inca. Its protein profile is unusually complete for a plant food, supplying all nine essential amino acids that the human body cannot make on its own.

Steam power and the measurement of horsepower

James Watt did not invent the steam engine, but his 18th-century improvements - most famously a separate condenser - made it dramatically more efficient and helped drive the Industrial Revolution. His name lives on in the watt, the unit of power used to rate everything from light bulbs to engines. Interestingly, the older unit "horsepower" was popularised partly to market his engines to buyers who thought in terms of draft animals.

When a peace treaty redraws the map

The Treaty of Prague in 1866 ended the Austro-Prussian War and reshaped central Europe, easing Austria out of German affairs and strengthening Prussia's hand. A few decades later, the Treaty of Versailles (1919) settled the First World War, while the Treaty of Trianon (1920) carved up Hungary. Three treaties, three very different moments in European history - and a reminder of how often exam questions mix them up.